Fuel Guage; Sending unit?

Well, previously, I have read on here that the fuel sending units are shit on these trucks. And that the unit is in the tank. Well, what I ask is this; I fill my tank up and then start the truck afterwards. The needle will go up and tell me the corresponding level to the amount of fuel in the tank. But when I start driving, the needle goes down and past the E line and will stay there. And from then on, the needle will stay there 24/7.

So I have a big problem if I dunno how much gas I have! So what is my problem? some fuses or the unit? I'd like to fix this problem ASAP!

If you can provide the answer, please be as descriptive as possible on what to replace or where it is at. Thanks for any help guys!

mine has the exact same problem and i cant figure out what the fuck it is!

A blown fuse would not let any current get to ur unit-period.Bad fuel sending unit.Mine goes up to Full real slow when I fill truck up, but after it finally makes it it reads ok .One day I am sure that it will just lay there like road kill and not read at all.RIP sending unit.BJ

Alright, so what you say is that it is the fuel unit. And the way the guage reads means it correlates with the amount of wear on the unit? So which means, I'm already at the end of the road with the unit! Haha... Thats right, RIP sending unit!

So correct me if I'm wrong, the unit is in the tank? Which means I have to drain the tank, jack up the truck, and remove the tank. Then replace the unit. Put it all back in, reconnect all the wires, lower the truck, fill the tank, and hope that I did the job right?

IF you can safely get your truck up in the air enough to be able to get your gas tank unbolted and brought down with a jack slowly . you won't have to drain your tank - lower it down and pull the connections off - but mark your connection hoses . theres 3 . there air fuel in fuel out .you could mark the unit with a marker or tape to match bact up when you go to re inetall .



All it takes is some screws to unbolt the sending unit and it should come out - in the case your sending unit screws are rusted over get a set of easy outs and drill them out . Trying not to get shavings in your tank if possible. AND reinstall in the reverse . Should be fine .


For a sending unit - go to rockauto.com where i got my sending unit From they are quick to ship your part out . I've found alot of parts stores aren't carrying many parts for our trucks . So i had to research for where to get some parts.

found this on another board - person asked basically the same questions as you did here's the answer . and it does Revolve around the sending unit .



Answer
Most likely it is the sending unit, it has a slider that rubs against a coil of magnet wire. Over time this slider wears out and bends away from the coil of wire.

You'll probably either have to drop the tank and remove the sending unit to mend it or replace it.



Go here for fuel sending unit info.

,carcode,1190506,parttype,4436,partGroup,22,EPImodelID,6119,EPIengineID,218

same here, when i rebuilt the engine, i also replaced everything in the fuel system, fuel pump, sending unit, and all. it worked for a while then it did the same thing so i replaced the sending unit thinking that was my problem. nope! i bought the mazda sending unit and when i changed it it was still under warranty so i didn't have to buy another one thank god! didn't fix the problem, so i pulled the gauge out of my parts truck and put it in my daily and it worked for a day! like you said it just reads empty all of the time now. i just fill up about every 300 miles and leave it until i put my fiberglass dash with digital gauges in it. don't know what the hell is wrong with it!

it would be easier to pull the bed than drop the tank....six bolts on the bed to the frame, remove the screws @ the filler neck......you an another buddy pick bed up off frame....easy access to the top of the tank......clean off the top of the tank real good when you pull the unit be carefull not to get any trash into the tank....put new one in, put bed back on......your done.

Eh, I'm sure it would'nt be too hard to do... Just as long as I know all the bolting locations. I have a manual so it might give me a blowup diagram. Although, I'm pretty sure I need to relieve the pressure to the tank, but how would you go about doin this?

Thankfully Autozone in my city, has them, and they are $50. From what it looks like, they have this rod protruding out from the shaft and a rubber piece connected to it. The rubber rides on the top of the gasoline, and wher the rod is situated inside of it depending on the level of gas, sends a current to the guage? I figure thats how it would go... Just makes me mad over the fact it just a simple little part.

Wonder if maybe I should call the Mazda dealership, they might have the answer to troubleshooting this problem. Fiberglassing the dash, sounds like a really good idea! Although, you would probably have to mud it to make it smooth. And which may crack over time from xtreme bass.

As for pullin the bed, it does'nt sound like a half bad idea. I know how to do that like the back of my hand. But my dad has a bad back, one person cannot lift that box!

But I do agree, pulln the bed is going to make it ALOT easier to the tank.

JUST FROM WHAT IVE SEEN AND HEARD, ON TOP OF THE THE SENDING UNIT, WHERE THE HARNESS PLUGS UP TO THE TWO PRONG CONNECTOR, RUST AND DIRT BUILDS UP BETWEEN THE THE PRONGS AND THE SENDING UNIT WHERE THE TWO RIVITS ARE.

ANOTHER IS WHAT YOUVE PROBALLY HEARD ALREADY. WHERE THE FLOAT IN THE TANK RIDES UP AND DOWN ON THE PICK UP, IT WILL WEAR OUT THE BOARD SENDING A DIFFRENT OHM READING WHICH WILL THROW OFF YOUR NEEDLE